Hybrid spa heater

ABSTRACT

A hybrid spa heater is disclosed. In a particular embodiment, the hybrid spa heater includes a cavitation fitting, where the cavitation fitting includes a plurality of orifices adapted to use water pressure to force water through to increase water temperature. The hybrid spa heater also includes an electric heater in fluid communication with the cavitation fitting, where the electric heater is adapted to increase the water temperature when an electrical resistance is applied. In addition, the cavitation fitting includes a chamber in downstream fluid communication with the plurality of orifices and is adapted to create a fluid vortex within the cavitation fitting to increase the water temperature. The cavitation fitting includes internal threading to mate with external threading of a water pump housing to allow the cavitation fitting to be removed for inspection and cleaning.

I. CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/261,621 filed Nov. 16, 2009. The disclosure of the provisionalapplication is incorporated herein by reference.

II. FIELD

The present disclosure is generally related to a hybrid spa heater.

III. DESCRIPTION OF RELATED ART

A typical spa or hot tub recirculates hot water using a pump and anelectrical heater. The electrical heater includes a resistance typeelectrical element that is in contact with the water. The water isheated as it passes proximate to the electrical element. A thermostat isused to control the water heater. The pump controls the volume of waterand velocity of water being forced out through the jets on the sides ofthe spa. A spa usually will have at least a high and low flow settingfor the pump. Electrical heaters will work on either the high or lowflow setting but are generally not energy efficient.

Another type of heater that may be used in heating the spa is called afriction heater. A friction heater generates heat using friction betweentwo surfaces such as a rotating drum and liner. The water is heated thatis contained adjacent to the liner. Yet another example includes arotating drum housing having an external surface which engages a boresurface of the housing. An external surface of the housing includes agroove around it with copper tubing wound around the groove. Thefriction caused by the rotating drum relative to the groove generatesheat in the housing which in turn heats the water flowing through thecopper tubing. However, it is difficult to maintain contact between thetwo surfaces to generate sufficient heat through friction.

Accordingly, what is needed in the art is a hybrid spa heater that isenergy efficient and reliable.

However, in view of the prior art at the time the present invention wasmade, it was not obvious to those of ordinary skill in the pertinent arthow the identified needs could be fulfilled.

IV. SUMMARY

In a particular embodiment, a hybrid spa heater is disclosed. The hybridspa heater includes a cavitation fitting, where the cavitation fittingincludes a plurality of orifices adapted to use water pressure to forcewater through to increase water temperature. In addition, the cavitationfitting includes a chamber in downstream fluid communication with theplurality of orifices and is adapted to create a fluid vortex within thecavitation fitting to increase the water temperature. The plurality oforifices is disposed on a removable disc adapted to insert into thecavitation fitting upstream of the chamber. The hybrid spa heater alsoincludes an electric heater in fluid communication with the cavitationfitting, where the electric heater is adapted to increase the watertemperature when an electrical resistance is applied. The hybrid spaheater may include a water pump having an inlet port and an outlet portwith the cavitation fitting in fluid communication with the outlet portof the water pump, where the water pump is adapted to increase an outletwater pressure to be greater than an inlet water pressure at the inletport. A control module may be used to control the electric heater inresponse to a user selecting a desired water speed or temperature. Thecavitation fitting includes internal threading to mate with externalthreading of a water pump housing to allow the cavitation fitting to beremoved for inspection and cleaning.

In another particular embodiment, a method to heat spa water isdisclosed. The method includes providing a cavitation fitting, where thecavitation fitting comprises a plurality of orifices adapted to usewater pressure to force water through to increase water temperature. Themethod also includes increasing the water temperature when an electricalresistance is applied to an electric heater in fluid communication withthe cavitation fitting, and creating a vortex within a chamber of thecavitation fitting downstream of the plurality of orifices to increasethe water temperature. In addition, the method includes inserting aremovable disc having the plurality of orifices into the cavitationfitting upstream of the chamber and increasing an outlet water pressureto be greater than an inlet water pressure of a water pump in fluidcommunication with the cavitation fitting. Further, the method includescontrolling an electric heater in response to a user selecting a desiredwater speed or temperature and mating the cavitation fitting to a waterpump housing to allow the cavitation fitting to be removed forinspection and cleaning.

Other aspects, advantages, and features of the present disclosure willbecome apparent after review of the entire application, including thefollowing sections: Brief Description of the Drawings and DetailedDescription.

V. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a particular embodiment of a hybrid spaheater;

FIG. 2 is a cross-sectional view of a cavitation fitting of the hybridspa heater;

FIG. 3 is a top view of a disc used within the cavitation fittingillustrated in FIG. 2;

FIG. 4 is a diagram of the hybrid spa heater and flow path recirculatingwater to the spa; and

FIG. 5 is a method of heating water using a hybrid spa heater.

VI. DETAILED DESCRIPTION

A first particular illustrative embodiment of a hybrid spa heater isdisclosed in FIG. 1 and generally designated 100. A water pump 102 is influid communication with a cavitation fitting 104. The cavitationfitting is secured to the outlet port of the pump 104. The cavitationfitting 104 is in fluid communication with the spa as shown in FIG. 1.An electric heater 106 is in fluid communication with the inlet port ofthe pump 102. Water from the spa flows to the electric heater 106 to theinlet port (suction) of the pump 102, through the impeller of the pump102, to the cavitation fitting 104 and back to the spa or othertreatment processes.

For example, in operation water is recirculated from the spa using thepump 102. When the spa (i.e., pump 102) is on low speed, then the wateris heated using the electric heater 106. The electric heater 106includes an electrical heating element that transfers heat to the water.When the pump 102 is on high speed, the cavitation fitting 104 heats thewater and the electric heater 106 is turned off in one embodiment. Inanother embodiment, the electric heater 106 works in conjunction withthe cavitation fitting 104 to heat the water until the electric heater106 is no longer required to heat (or maintain) the water to a desiredtemperature and the cavitation fitting 104 does the heating. This makesthe hybrid spa heater 100 increasingly energy efficient.

The pump 102 may be a centrifugal pump, which includes an impellerrotating within a case. Water enters the impeller in the center portion,flows outwardly, and is discharged around the entire circumference intoa casing. The water receives in increase in both pressure and absolutevelocity from flowing through the rotating impeller. As a large part ofthe energy of the water leaving the impeller is kinetic, the absolutevelocity is reduced to transform the velocity head into a pressure headat the outlet port of the pump 102. An axial flow pump may also be usedwith the hybrid spa heater 100.

A cross sectional view of the cavitation fitting 104 is illustrated inFIG. 2. The outlet port 212 of the water pump housing may includeexternal threading to mate with internal threading 210 of a lowerportion of the cavitation fitting 104. This allows the cavitationfitting 104 to be easily removed for inspection and cleaning to increasethe heating efficiency. In addition, the cavitation fitting 104 includesa chamber 208 in downstream fluid communication with a plurality oforifices within the cavitation fitting 104, which the orifices areadapted to create a fluid vortex within the cavitation fitting 104 toincrease the water temperature. Alternatively, the cavitation fitting104 may use channels, sections, conduits, or any combination thereof,that are adapted to generate heat.

Referring now to FIG. 3, the plurality of orifices may be disposed on aremovable disc 202 adapted to insert into the cavitation fitting 104upstream of the chamber 208. The number of orifices 302 andconfiguration may vary depending on the size and rating of the pump 102and a particular specific application.

The typical flow path of the water circulated with the hybrid spa heateris illustrated in FIG. 4. For example, the spa 110 holds most of thewater. The water flows into the spa 110 using jets. A control panel 108is used to adjust the temperature and speed of the water, for examplehigh or low flow. Pumps are customarily rated in gallons per minute. Thepump 102 uses suction to remove water from the spa 110 and circulate thewater flow to the electric heater 106. The electric heater 106 may beused to transfer heat to the water under certain conditions. Theelectric heater 106 uses a resistive heating element to generate heat.The hybrid spa heater 100 determines when to use the electric heater 106depending on several factors. For example, the factors may include theenergy efficiency desired by a user (e.g., how long to heat the water),the flow rate of the water, and/or the desired temperature of the water,and any combination thereof. The water then flows through the impellerof the pump 102 which increases the pressure of the water as the wateris pumped to the cavitation fitting 104 secured to the outlet port 212of the pump 102. The cavitation fitting 104 may force the water at highpressure through small openings, channels, sections, conduits, orifices,or any combination thereof, to generate heat. If the water is not at asufficient velocity or pressure, then the cavitation fitting 104 may notbe as effective. The cavitation fitting 104 requires a high flow and/orpressure to generate heat. No other water heater uses a combination of acavitation fitting 104 and electric heater 106 that is dependent onthese types of factors.

A particular method of heating water with a hybrid spa heater isdisclosed in FIG. 5 and generally designated 400. Water from a spa isrecirculated using a pump, at 402. The hybrid spa heater determines, at404, whether the pump is on a low speed (flow) or high speed. Acavitation fitting that is in fluid communication with the pump is used,at 406, when the pump is on high speed to increase a temperature of thewater. The cavitation fitting is configured to force the water to flowthough small openings, channels, sections, conduits, orifices, or anycombination thereof, to generate heat. Continuing to 408, an electricheater is in fluid communication with the pump when the pump is on lowspeed or high speed to increase the temperature of the water. Theelectric heater includes an electrical heating element to generate heatto transfer to the water. The water is then recirculated, at 410, backto the spa.

The illustrations of the embodiments described herein are intended toprovide a general understanding of the structure of the variousembodiments. The illustrations are not intended to serve as a completedescription of all of the elements and features of apparatus and systemsthat utilize the structures or methods described herein. Many otherembodiments may be apparent to those of skill in the art upon reviewingthe disclosure. Other embodiments may be utilized and derived from thedisclosure, such that structural and logical substitutions and changesmay be made without departing from the scope of the disclosure.Accordingly, the disclosure and the figures are to be regarded asillustrative rather than restrictive.

One or more embodiments of the disclosure may be referred to herein,individually and/or collectively, by the term “invention” merely forconvenience and without intending to voluntarily limit the scope of thisapplication to any particular invention or inventive concept. Moreover,although specific embodiments have been illustrated and describedherein, it should be appreciated that any subsequent arrangementdesigned to achieve the same or similar purpose may be substituted forthe specific embodiments shown. This disclosure is intended to cover anyand all subsequent adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the description. Thus, the present disclosure is notintended to be limited to the embodiments shown herein but is to beaccorded the widest scope possible consistent with the principles andnovel features as defined by the following claims.

1. A hybrid spa heater, the heater comprising: a cavitation fitting,wherein the cavitation fitting comprises a plurality of orifices adaptedto use water pressure to force water therethrough to increase watertemperature; and an electric heater in fluid communication with thecavitation fitting, wherein the electric heater is adapted to increasethe water temperature when an electrical resistance is applied.
 2. Thehybrid spa heater of claim 1, the cavitation fitting further comprisinga chamber in downstream fluid communication with the plurality oforifices and adapted to create a fluid vortex within the cavitationfitting to increase the water temperature.
 3. The hybrid spa heater ofclaim 2, wherein the plurality of orifices is disposed on a removabledisc adapted to insert into the cavitation fitting upstream of thechamber.
 4. The hybrid spa heater of claim 3, further comprising a waterpump having an inlet port and an outlet port, the cavitation fitting influid communication with the outlet port of the water pump, wherein thewater pump is adapted to increase an outlet water pressure to be greaterthan an inlet water pressure at the inlet port.
 5. The hybrid spa heaterof claim 4, further comprising a control module that controls theelectric heater in response to a user selecting a desired water speed ortemperature.
 6. The hybrid spa heater of claim 5, wherein the cavitationfitting further comprises internal threading to mate with externalthreading of a water pump housing to allow the cavitation fitting to beremoved for inspection and cleaning.
 7. The hybrid spa heater of claim6, wherein the water pump is a centrifugal pump.
 8. The hybrid spaheater of claim 7, the water pump further comprising a variable speedmotor.
 9. The hybrid spa heater of claim 8, wherein the cavitationfitting is a polyvinyl chloride material.
 10. The hybrid spa heater ofclaim 8, wherein the plurality of orifices are sized to increase avelocity of water through the cavitation fitting.
 11. A method ofheating water for a spa, the method comprising: providing a cavitationfitting, wherein the cavitation fitting comprises a plurality oforifices adapted to use water pressure to force water therethrough toincrease water temperature; and increasing the water temperature when anelectrical resistance is applied to an electric heater in fluidcommunication with the cavitation fitting.
 12. The method of claim 11,further comprising creating a vortex within a chamber of the cavitationfitting downstream of the plurality of orifices to increase the watertemperature.
 13. The method of claim 12, further comprising inserting aremovable disc having the plurality of orifices into the cavitationfitting upstream of the chamber.
 14. The method of claim 13, furthercomprising increasing an outlet water pressure to be greater than aninlet water pressure of a water pump in fluid communication with thecavitation fitting.
 15. The method of claim 14, further comprisingcontrolling an electric heater in response to a user selecting a desiredwater speed or temperature.
 16. The method of claim 15, furthercomprising mating the cavitation fitting to a water pump housing toallow the cavitation fitting to be removed for inspection and cleaning.17. The method of claim 16, wherein the water pump is a centrifugalpump.
 18. The method of claim 17, further comprising adjusting a speedof a motor for the pump to correspondingly adjust the outlet waterpressure.